35 lines
678 B
C
35 lines
678 B
C
#include "libc/math/libm.h"
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#if LDBL_MANT_DIG == 53 && LDBL_MAX_EXP == 1024
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long double truncl(long double x)
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{
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return trunc(x);
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}
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#elif (LDBL_MANT_DIG == 64 || LDBL_MANT_DIG == 113) && LDBL_MAX_EXP == 16384
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static const long double toint = 1/LDBL_EPSILON;
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long double truncl(long double x)
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{
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union ldshape u = {x};
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int e = u.i.se & 0x7fff;
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int s = u.i.se >> 15;
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long double y;
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if (e >= 0x3fff+LDBL_MANT_DIG-1)
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return x;
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if (e <= 0x3fff-1) {
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FORCE_EVAL(x + 0x1p120f);
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return x*0;
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}
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/* y = int(|x|) - |x|, where int(|x|) is an integer neighbor of |x| */
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if (s)
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x = -x;
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y = x + toint - toint - x;
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if (y > 0)
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y -= 1;
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x += y;
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return s ? -x : x;
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}
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#endif
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